scholarly journals AlN-on-Si Square Diaphragm Piezoelectric Micromachined Ultrasonic Transducer with Extended Range of Detection

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 913 ◽  
Author(s):  
Suresh Alasatri ◽  
Libor Rufer ◽  
Joshua En-Yuan Lee
Keyword(s):  
Printed Circuit Board ◽  
Ultrasonic Transducer ◽  
Ultrasonic Transducers ◽  
Circuit Board ◽  
Detection Range ◽  
Range Finding ◽  
Sensing Applications ◽  
Current State ◽  
Wire Bonds ◽  
Extended Range

We present aluminum nitride (AlN) on silicon (Si) CMOS-compatible piezoelectric micromachined ultrasonic transducers (pMUTs) with an extended detection range of up to 140 cm for touchless sensing applications. The reported performance surpasses the current state-of-art for AlN-based pMUTs in terms of the maximum range of detection using just a pair of pMUTs (as opposed to an array of pMUTs). The extended range of detection has been realized by using a larger diaphragm allowed by fabricating a thicker diaphragm than most other pMUTs reported to date. Using a pair of pMUTs, we experimentally demonstrate the capability of range-finding by correlating the time-of-flight (TOF) between the transmit (TX) and receive (RX) pulse. The results were obtained using an experimental setup where the MEMS chip was interconnected with a customized printed circuit board (PCB) using Al wire bonds.

A Comparison of Immersion Gold and Tin Surface Finishes on Sensing Electrodes for PCB Environmental Saltwater Concentration Sensors

2016 ◽  
Vol 2016 (1) ◽  
pp. 000557-000562
Author(s):  
Robert N. Dean ◽  
Frank T. Werner ◽  
Michael J. Bozack
Keyword(s):  
Surface Finish ◽  
Printed Circuit Board ◽  
Chemical Constituents ◽  
Low Cost ◽  
Circuit Board ◽  
Testing Environment ◽  
Printed Circuit ◽  
Sensor Performance ◽  
Sensing Applications ◽  
Surface Finishes

Abstract Printed circuit board (PCB) sensors using low-cost commercial printed circuit board fabrication processes have been demonstrated for environmental sensing applications. One configuration of these sensors uses exposed electrodes to measure saltwater concentration in freshwater/seawater mixtures, through monitoring the resistance between the electrodes when they are immersed in the saltwater/freshwater solution. The lowest cost commercial PCB processes use an immersion Sn HASL surface finish on exposed copper cladding, including the sensing electrodes. This commercial PCB process has been demonstrated to make an effective, low-cost, short-lifetime sensor for saltwater concentration testing. The Sn finish, however, may not be optimal for this application. Sn oxidizes, which can interfere with sensor performance. Additionally, Sn and Sn oxides are potentially reactive with chemical constituents in seawater and seawater/freshwater solutions. An immersion Au (ENIG) surface finish is certainly less reactive with the atmosphere and chemicals likely present in the testing environment. However, an immersion Au finish increases the cost of the sensors by 30% to 40%. To investigate if the possible benefits of the more expensive Au surface finish are worth the extra expense, a study was performed where identical PCB sensors were procured from a commercial vendor with their standard low-cost Sn HASL finish and with their standard ENIG surface finish. Both sets of sensors were then evaluated in concentrations of seawater and freshwater, from 0% to 100% seawater concentration, using freshwater samples from a natural freshwater source near the coast where the seawater was obtained. Testing demonstrated an insignificant difference in sensor performance between the Sn HASL and the ENIG coated sensing electrodes. The results of this investigation indicated that for applications where the sensors will not be used for long periods of time, the added expense of an immersion Au surface finish is not worth the added cost.

On the Way from Fan-out Wafer to Fan-out Panel Level Packaging

2016 ◽  
Vol 2016 (S2) ◽  
pp. S1-S23 ◽  
Author(s):  
Karl-Friedrich Becker ◽  
Tanja Braun ◽  
S. Raatz ◽  
M. Minkus ◽  
V. Bader ◽  
...  
Keyword(s):  
Flip Chip ◽  
Printed Circuit Board ◽  
Layer Structure ◽  
Form Factors ◽  
Circuit Board ◽  
Wafer Level ◽  
Wafer Level Packaging ◽  
Bga Packages ◽  
Wire Bonds ◽  
Near Future

Fan-out Wafer Level Packaging (FOWLP) is one of the latest packaging trends in microelectronics. The technology has a high potential in significant package miniaturization concerning package volume but also in thickness. Main advantages of FOWLP are the substrate-less package, lower thermal resistance, higher performance due to shorter interconnects together with direct IC connection by thin film metallization instead of wire bonds or flip chip bumps and lower parasitic effects. Especially the inductance of the FOWLP is much lower compared to FC-BGA packages. In addition the redistribution layer can also provide embedded passives (R, L, C) as well as antenna structures using a multi-layer structure. It can be used for multi-chip packages for System in Package (SiP) and heterogeneous integration. Manufacturing is currently done on wafer level up to 12″/300 mm and 330 mm respectively. For higher productivity and therewith lower costs larger form factors are forecasted for the near future. Instead of following the wafer level approach to 450 mm, panel level packaging will be the next big step. Sizes for the panel could range up to 18″×24″ or even larger influenced by different technologies coming from e.g. printed circuit board, solar or LCD manufacturing. However, an easy upscaling of technology when moving from wafer to panel level is not possible. Materials, equipment and processes have to be further developed or at least adapted. An overview of state of technology for panel level packaging will be presented and discussed in detailed.

scholarly journals Microfluidic Mixer with Automated Electrode Switching for Sensing Applications

Chemosensors ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 13 ◽  
Author(s):  
Maria L. Braunger ◽  
Igor Fier ◽  
Varlei Rodrigues ◽  
Paulo E. Arratia ◽  
Antonio Riul
Keyword(s):  
Printed Circuit Board ◽  
Electronic Tongue ◽  
Microfluidic Devices ◽  
Circuit Board ◽  
Physical Interaction ◽  
Layer By Layer ◽  
Passive Mixer ◽  
Microfluidic Mixer ◽  
Sensing Applications ◽  
Food And Beverage

An electronic tongue (e-tongue) is a multisensory system usually applied to complex liquid media that uses computational/statistical tools to group information generated by sensing units into recognition patterns, which allow the identification/distinction of samples. Different types of e-tongues have been previously reported, including microfluidic devices. In this context, the integration of passive mixers inside microchannels is of great interest for the study of suppression/enhancement of sensorial/chemical effects in the pharmaceutical, food, and beverage industries. In this study, we present developments using a stereolithography technique to fabricate microfluidic devices using 3D-printed molds for elastomers exploring the staggered herringbone passive mixer geometry. The fabricated devices (microchannels plus mixer) are then integrated into an e-tongue system composed of four sensing units assembled on a single printed circuit board (PCB). Gold-plated electrodes are designed as an integral part of the PCB electronic circuitry for a highly automated platform by enabling faster analysis and increasing the potential for future use in commercial applications. Following previous work, the e-tongue sensing units are built functionalizing gold electrodes with layer-by-layer (LbL) films. Our results show that the system is capable of (i) covering basic tastes below the human gustative perception and (ii) distinguishing different suppression effects coming from the mixture of both strong and weak electrolytes. This setup allows for triplicate measurements in 12 electrodes, which represents four complete sensing units, by automatically switching all electrodes without any physical interaction with the sensor. The result is a fast and reliable data acquisition system, which comprises a suitable solution for monitoring, sequential measurements, and database formation, being less susceptible to human errors.

scholarly journals Reprogrammable plasmonic topological insulators with ultrafast control

2021 ◽  
Author(s):  
Jian Wei You ◽  
Qian Ma ◽  
Zhihao Lan ◽  
Qiang Xiao ◽  
Nicolae Panoiu ◽  
...  
Keyword(s):  
Topological Insulator ◽  
High Speed ◽  
Topological Insulators ◽  
Light Propagation ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Current State ◽  
Intelligent Devices ◽  
Optical Analog ◽  
Magnitude Improvement

Abstract Topological photonics has revolutionized our understanding of light propagation, providing a remarkably robust way to manipulate light. Despite the intensive research and rapid progress in this field, most of existing studies are focused on designing a static photonic structure to realize a specific topological functionality or phenomenon. Developing a dynamic and universal photonic topological platform to intelligently switch multiple topological functionalities at ultrafast speed is still a great challenge. Here we theoretically propose and experimentally demonstrate an ultrafast reprogrammable plasmonic topological insulator, where the topological propagation route can be dynamically changed at nanosecond-level switching time, which is more than 1×10^7 times faster than the current state-of-the-art, leading to an experimental demonstration of unprecedentedly ultrafast multi-channel optical analog-digital converter. This orders-of-magnitude improvement compared to previous works is due to the innovative use of ultrafast electric switches to implement the programmability of our plasmonic topological insulator, which enables us to precisely encode each unit cell by dynamically controlling its digital plasmonic states while keeping its geometry and material parameters unchanged. Our reprogrammable topological plasmonic platform can be fabricated by the widely-used printed circuit board technology, making it much more attractive and compatible with current highly integrated photoelectric systems. Furthermore, due to its flexible programmability, many existing photonic topological functionalities can be integrated into this versatile topological platform. Our work brings the current studies of photonic topological insulators to a digital and intelligent era, which could open new avenues towards the development of software-defined photoelectric elements in high-speed communications and computation-based intelligent devices with built-in topological protection.

Heterogeneous Process Development for Electronic Device Packaging with Direct Printed Additive Manufacturing

2012 ◽  
Vol 2012 (1) ◽  
pp. 000961-000966
Author(s):  
R. X. Rodriguez ◽  
K. Church ◽  
X. Chen
Keyword(s):  
Additive Manufacturing ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Process Development ◽  
Electronic Device ◽  
Circuit Board ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Wire Bonds ◽  
The Status

Next generation electronics will not change drastically in function; batteries will last longer, devices will have more functions and devices will take unique shapes, but for the next several years, electronics will travel the path it has been traveling for a couple of decades. To meet the demands of more functions per device and unique shapes, the status quo of electronic manufacturing cannot persist. Solder, wire bonds, FR4, printed circuit boards, surface mount and packaging will fight for survival, but just as hand held phones have evolved, so will the electronics that support them. Standard electronic packaging techniques are reaching size and density limits forcing a search for alternative approaches. The idea of using Additive Manufacturing as an alternative for packaging has not been taken seriously, but there is an opportunity to demonstrate the significant advantages of true 3D electronic packages by allowing the package to be the printed circuit board and by utilizing direct print and bare die approaches to print and structure diverse electronics.

scholarly journals Rapid Inkjet-Printed Miniaturized Interdigitated Electrodes for Electrochemical Sensing of Nitrite and Taste Stimuli

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1037
Author(s):  
Sohan Dudala ◽  
Sangam Srikanth ◽  
Satish Kumar Dubey ◽  
Arshad Javed ◽  
Sanket Goel
Keyword(s):  
Inkjet Printing ◽  
Glass Substrate ◽  
Printed Circuit Board ◽  
Electrochemical Impedance ◽  
Single Step ◽  
Electrochemical Sensing ◽  
Circuit Board ◽  
Interdigitated Electrodes ◽  
Sensing Applications ◽  
Direct Laser

This paper reports on single step and rapid fabrication of interdigitated electrodes (IDEs) using an inkjet printing-based approach. A commercial inkjet-printed circuit board (PCB) printer was used to fabricate the IDEs on a glass substrate. The inkjet printer was optimized for printing IDEs on a glass substrate using a carbon ink with a specified viscosity. Electrochemical impedance spectroscopy in the frequency range of 1 Hz to 1 MHz was employed for chemical sensing applications using an electrochemical workstation. The IDE sensors demonstrated good nitrite quantification abilities, detecting a low concentration of 1 ppm. Taste simulating chemicals were used to experimentally analyze the ability of the developed sensor to detect and quantify tastes as perceived by humans. The performance of the inkjet-printed IDE sensor was compared with that of the IDEs fabricated using maskless direct laser writing (DLW)-based photolithography. The DLW–photolithography-based fabrication approach produces IDE sensors with excellent geometric tolerances and better sensing performance. However, inkjet printing provides IDE sensors at a fraction of the cost and time. The inkjet printing-based IDE sensor, fabricated in under 2 min and costing less than USD 0.3, can be adapted as a suitable IDE sensor with rapid and scalable fabrication process capabilities.

Automated Via Detection for PCB Reverse Engineering

2020 ◽  
Author(s):  
Ulbert J. Botero ◽  
David Koblah ◽  
Daniel E. Capecci ◽  
Fatemeh Ganji ◽  
Navid Asadizanjani ◽  
...  
Keyword(s):  
Reverse Engineering ◽  
Printed Circuit Board ◽  
Similarity Index ◽  
Structural Similarity ◽  
Detection Algorithm ◽  
Fine Tuning ◽  
Circuit Board ◽  
Electronic Systems ◽  
Current State ◽  
X Ray Computed

Abstract Reverse engineering (RE) is the only foolproof method of establishing trust and assurance in hardware. This is especially important in today's climate, where new threats are arising daily. A Printed Circuit Board (PCB) serves at the heart of virtually all electronic systems and, for that reason, a precious target amongst attackers. Therefore, it is increasingly necessary to validate and verify these hardware boards both accurately and efficiently. When discussing PCBs, the current state-of-the-art is non-destructive RE through X-ray Computed Tomography (CT); however, it remains a predominantly manual process. Our work in this paper aims at paving the way for future developments in the automation of PCB RE by presenting automatic detection of vias, a key component to every PCB design. We provide a via detection framework that utilizes the Hough circle transform for the initial detection, and is followed by an iterative false removal process developed specifically for detecting vias. We discuss the challenges of detecting vias, our proposed solution, and lastly, evaluate our methodology not only from an accuracy perspective but the insights gained through iteratively removing false-positive circles as well. We also compare our proposed methodology to an off-the-shelf implementation with minimal adjustments of Mask R-CNN; a fast object detection algorithm that, although is not optimized for our application, is a reasonable deep learning model to measure our work against. The Mask R-CNN we utilize is a network pretrained on MS COCO followed by fine tuning/training on prepared PCB via images. Finally, we evaluate our results on two datasets, one PCB designed in house and another commercial PCB, and achieve peak results of 0.886, 0.936, 0.973, for intersection over union (IoU), Dice Coefficient, and Structural Similarity Index. These results vastly outperform our tuned implementation of Mask R-CNN.

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